To study the design and functionality of the mainstream and entry-level chipsets for the AMD Bulldozer platform we decided to go with two mainboards from Asus: Asus M5A99X EVO and Asus M5A97 EVO, based on AMD 990X and AMD 970 chipsets respectively. In our today’s review we are going to compare them against one another as well as against the previously tested mainboards on the top Socket AM3+ core logic set.

PCB Design and Functionality

The two mainboards seem to be almost identical at first sight, but there are actually quite a lot of differences on closer inspection.

Asus M5A99X EVO

Asus M5A97 EVO

Compared to ASUS's flagship AMD-based mainboards, the CPU voltage regulator has been simplified from 8+2 to 6+2 design. The cooling systems look identical on both mainboards, but the North Bridge heatsink is secured with screws on the M5A99X EVO and connected with a heat pipe to the CPU VRM heatsink. The junior mainboard’s heatsinks are fastened with spring-loaded plastic locks and lack any heat pipes.

The M5A97 EVO has six SATA 6 Gbit/s ports, two of which are placed aside of the others. The M5A99X EVO, on its part, also has six SATA 6 Gbit/s ports thanks to the AMD SB950 South Bridge but complements them with two SATA 3 Gbit/s ports based on a JMicron JMB362 controller.

Asus M5A99X EVO

Asus M5A97 EVO

It’s in the expansion slot area that we see the biggest differences between the two models. They are due to the different chipsets, of course. The M5A99X EVO is equipped with one PCI, two PCI Express 2.0 x1 and three PCI Express 2.0 x16 slots. It supports one graphics card at full x16 speed or two graphics cards (in CrossFireX or SLI mode with up to 4 GPUs) at x8 speed each. The third x16 slot is connected to four PCIe lanes provided by the South Bridge. The junior mainboard has two PCI, two PCI Express 2.0 x1 and two PCI Express 2.0 x16 slots but the top slot is the only one to work at full speed. The bottom slot is x4. The mainboard supports Quad-GPU CrossFireX but not SLI.

Here is the complete list of all ports and connectors on the back of our ASUS M5A99X EVO:

PS/2 connector for keyboard or mouse;

Eight USB 2.0 ports, six more can be connected to three onboard pin-headers;

IEEE1394 (FireWire) port implemented via VIA VT6308P controller, the second port is available as onboard pin-connector;

Two eSATA 3 Gbps port implemented via JMicron IMB362 controller, one of which is Power eSATA (green connector). The second controller like that adds support for another two internal SATA ports;

Two USB 3.0 ports (blue connectors) implemented via ASMedia ASM1042 controller, second controller like that provides an additional internal pin-connector for two more USB 3.0 ports;

A local network port (network adapter is built on Gigabit Realtek RTL8111E controller).

The mainboards' back panels differ a lot. Take a look at the M5A97 EVO's:

The selection of I/O ports is almost the same, though. They are just arranged in a different way. The single difference is that the junior model's back panel offers two ordinary eSATA 3 Gbit/s ports whereas the senior model has one port of the Power eSATA variety.

Asus M5A99X EVO

Asus M5A97 EVO

The mainboards both have a number of features typical of other ASUS products such as the MemOK! button that helps start the computer up in case of some memory-related problems. The graphics slots are equipped with handy Q-Slot latches whereas the memory slots have Q-DIMM latches on one side only. In case of some problems, the Q-LED indicators report the step at which the boot-up process has been halted. The TPU switch can be used to overclock the CPU automatically while the EPU switch enables power-saving operation modes.

The M5A99X EVO offers five fan connectors, two of which are of the 4-pin variety. The junior model has two 3-pin and two 4-pin fan connectors. The mainboards can regulate the speed of each connected fan depending on temperature, except for the fan marked as Power FAN.

For your reference all mainboards' specifications have been summed up in the following table: